HPV Strain 18 and Cancer Risk Timeline

Hello, My girlfriend recently tested positive for HPV and we've gone to the doctor twice to confirm. She was tested 2 years ago for HPV and was negative. Everything I find online (CDC website primarily) says an HPV negative test result means you absolutely can't have HPV at the time (i.e. even if it's dormant, it'll still come up positive if you have it). Does anyone know if it's true (according to the CDC website they say it is), if the woman has even a dormant case of HPV and gets the real HPV test, it'll come back positive? I'm trying to figure out how long I've possibly had it for now as the tests aren't offered to men and am wondering about my status. Thank you.